Oscar Pistorius has an anxiety disorder murder trial hears

A FORENSIC psychiatrist told a court in Pretoria that Oscar Pistorius has an anxiety disorder and is a "distrusting and guarded" person.

Forensic psychiatrist Dr. Merryl Vorster described the athlete - who is charged with murdering girlfriend Reeva Steencamp - as a "distrusting and guarded" person who is "hyper-vigilant" about security and often feels "isolated and alone" as she took the stand at the North Gauteng High Court in Pretoria.

However, her evidence caused state prosecutor Gerrie Nel to argue the athlete's mental health should be examined more fully, which could delay the trial for up to a month if he is admitted to a psychiatric hospital for tests.

Pistorius claims he shot his partner after mistaking her for an intruder, and the psychiatrist spoke at length about his "fight or flight response", claiming he is more likely to stand up to threatening situations than to flee because of his disability.

She also said: "When in South Africa he worries about being followed and about the security of his home."

She spoke of how he sleeps with his bedroom door locked and frequent night wakings, believing he hears noises, explaining his increased anxiety levels mean he "perceives his surroundings as being threatening when perhaps they're not".

If the 27-year-old athlete is found to be suffering from a mental illness, he could not be health criminally responsible for his girlfriend's death and would be found not guilty by reason of "mental illness or intellectual disability".

The trial was adjourned before prosecutors could make any formal application for a psychiatric referral.